U.S. patent number 4,496,989 [Application Number 06/390,373] was granted by the patent office on 1985-01-29 for method for composing and recording a picture and a character by using picture signals and character signals for use in a picture reproducing machine.
This patent grant is currently assigned to Dainippon Screen Seizo Kabushiki Kaisha. Invention is credited to Makoto Hirosawa.
United States Patent |
4,496,989 |
Hirosawa |
January 29, 1985 |
Method for composing and recording a picture and a character by
using picture signals and character signals for use in a picture
reproducing machine
Abstract
A method for composing and recording a picture and a character
by using picture signals and character signals, for use in a
picture reproducing machine such as a layout color scanner and a
color facsimile, wherein an original picture having a continuous
gradation is scanned to obtain a picture signal representing one
picture element area, wherein a recording signal representing one
recording picture element area corresponding to the one picture
element area is prepared from the picture signal, and wherein a
halftone picture is reproduced directly depending on the recording
signal, is disclosed. Each recording picture element area in which
the character is recorded, is sub-divided into a plurality of
character picture element areas, each corresponding to one
character picture element represented by one character signal
having two-value levels, and the picture signal and the character
signal are selectively output or composed as the recording signal
per one picture element, whereby reproducing a combination of the
picture and the character on a photosensitive material.
Inventors: |
Hirosawa; Makoto (Kyoto,
JP) |
Assignee: |
Dainippon Screen Seizo Kabushiki
Kaisha (Kyoto, JP)
|
Family
ID: |
14552683 |
Appl.
No.: |
06/390,373 |
Filed: |
June 21, 1982 |
Foreign Application Priority Data
|
|
|
|
|
Jul 16, 1981 [JP] |
|
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56-111111 |
|
Current U.S.
Class: |
358/296; 358/462;
358/521; 715/209 |
Current CPC
Class: |
H04N
1/4055 (20130101); H04N 1/3871 (20130101) |
Current International
Class: |
H04N
1/387 (20060101); H04N 1/405 (20060101); H04N
001/40 () |
Field of
Search: |
;358/75,280,256,257,78,296,283,298 ;364/523 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Britton; Howard W.
Attorney, Agent or Firm: Poms, Smith, Lande & Rose
Claims
What is claimed is:
1. A method for the economical recording and reproducing of images
including (1) picture areas of low spatial resolution having a wide
gradation of intensity levels, and character or letter areas which
are black or white but have higher spatial resolution requirements
comprising the steps of:
(1) recording the picture area elements of a first predetermined
size with a substantially continuous gradation of intensity, in
digital format;
(2) recording the character or letter areas by subdividing the said
predetermined picture element size to smaller areas of a second
predetermined size, together with indications as to whether each of
the smaller areas are black or white, in digital format;
(3) including as part of the recorded digital format for the
recorded information one bit which indicates whether the recorded
information represents a picture area as noted in (1) hereinabove,
or a character or letter area as noted in (2) hereinabove; and
(4) decoding and generating a new physical representation of the
combined picture and character or letter areas, with the picture
areas being reproduced in multiple intensity gradations with
relatively coarse spatial resolution, and the character or letter
areas being reproduced in half-tone or black and white with
relatively fine spatial definition or resolution.
2. A method as defined in claim 1 including the step of generating
the characters or letters by typing the characters or letters on a
keyboard.
3. A method as defined in claim 1 including the step of recording
character or letter areas which are one-fourth said first
predetermined size of the picture area elements.
4. A method as defined in claim 1 wherein the generation of the new
physical representation of said picture and character or letter
area includes (1) the application of signals to a recording medium
in the form of a series of parallel dots from a set of aligned
image generating elements, (2) the energization of a varying
proportion of said image-generating elements to represent picture
area intensity levels, and (3) the selective energization of spaced
ones of said image-generating elements to give improved spatial
representation of said character or letter areas.
5. A system: for the economical recording and reproducing of images
including (1) picture areas of low spatial resolution having a wide
gradation of intensity levels, and character or letter areas which
are black or white but have higher spatial resolution requirements
comprising:.
(1) means for recording the picture area elements of a first
predetermined size with a substantially continuous gradation of
intensity, in digital format;
(2) means for recording the character or letter areas by
subdividing the said predetermined picture element size to smaller
areas of a second predetermined size, together with indications as
to whether each of the smaller areas are black or white, in digital
format;
(3) means for including as part of the recorded digital format for
the recorded information one bit which indicates whether the
recorded information represents a picture area as noted in (1)
hereinabove, or a character or letter area as noted in (2)
hereinabove; and
(4) means for recording and generating a new physical
representation of the combined picture and character or letter
areas, with the picture areas being reproduced in multiple
intensity gradations with relatively coarse spatial resolution, and
the character or letter areas being reproduced in half-tone or
black and white with relatively fine spatial definition or
resolution.
6. A system as defined in claim 5 including means for generating
the characters or letters by typing the characters on a
keyboard.
7. A system as defined in claim 5 including means for recording a
digital representation of character or letter areas which are
one-fourth said first predetermined size of the picture area
elements.
8. A system as defined in claim 5 including means for recording the
black or white nature of several small character or letter areas in
a set of bits of digital information equal in length to the number
of bits of information representing the darkness level of larger
elemental picture areas each equal in extent to the several small
character or letter areas represented by said set of bits of
digital information.
9. A method as defined in claim 5 wherein the means for generating
a new physical representation of said picture and character or
letter areas includes (1) means for applying signals to a recording
medium in the form of a series of parallel dots from a set of
aligned image generating elements, (2) means for energizing a
varying proportion of said image generating elements to represent
picture area intensity levels, and (3) means for energizing
selected ones of said image generating elements to give improved
spatial representation of said character or letter areas.
10. A system as defined in claim 9 wherein said last mentioned
energizing means includes means for selectively turning a first
half and/or a second half of said image-generating elements on or
off.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a method for composing and
recording a picture having a continuous gradation and a character
having two-value levels such as white and black in the desired
layout positions by using picture signals and character signals in
a digital manner, for use in a picture reproducing machine such as
a color scanner and a color facsimile.
In a conventional picture reproducing machine such as a color
scanner for plate making, a plurality of original pictures can be
reproduced on a photosensitive material in the desired layout
positions. Some method have been developed for carrying out this.
Now, a picture having a continuous gradation and characters having
two-value levels such as white and black are expected to be
composed and recorded in the desired layout positions on a
photosensitive material.
When such a picture and characters composed are recorded in the
desired layout positions, since the characters composed of fine
lines and curves are recorded in the image having two-value levels
such as white and black, the characters should be processed with a
higher resolving power than the picture. Hence, when the picture is
processed with the same higher resolving power as the characters
should be, the processing time increases. Further, when the picture
is processed with much higher resolving power than it needs, the
capacity of the memory increases largely.
Further, when the picture and the characters are separately laid
out, two memories for the picture and the characters are required.
Each memory for the layout should have a memory space for storing
picture signals corresponding to at least one picture but usually a
plurality of pictures. Hence, in this case, two memories having a
large capacity are necessary, which is uneconomical.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method for
composing and recording a picture having a continuous gradation and
characters having two-value levels such as white and black in the
desired layout positions by using picture signals and character
signals, for use in a picture reproducing machine such as a color
scanner and a color facsimile, free from the aforementioned
disadvantages and inconveniences, which is quick, reliable and
economical.
According to the present invention there is provided a method for
composing and recording a picture and a character by using picture
signals and character signals, for use in a picture reproducing
machine wherein an original picture having a continuous gradation
is scanned to obtain a picture signal which represents one picture
element area, wherein a recording signal which represents one
recording picture element area corresponding to the one picture
element area, is prepared from the picture signal, and wherein a
halftone picture is reproduced directly depending on the recording
signal, the improvement wherein each recording picture element area
in which the character picture element areas, each corresponding to
one character picture element represented by one character signal
having two-value levels, and wherein either picture signal or
character signals are selectively output as the recording signal
per one picture element, whereby reproducing a combination of the
picture and the character on a photosensitive material.
According to the present invention there is also provided a method
for composing and recording a picture and a character by using
picture signals and character signals, for use in a picture
reproducing machine wherein an original picture having a continuous
gradation is scanned to obtain a picture signal which represents
one picture element area, wherein a recording signal which
represents one recording picture element area corresponding to the
one picture element area, is prepared from the picture signal, and
wherein a halftone picture is reproduced directly depending on the
recording signal, the improvement wherein each recording picture
element area in which the character is recorded, is subdivided into
a plurality of character picture element areas, each corresponding
to one character picture element represented by one character
signal having two-value levels, and wherein the picture signal and
the character signals are composed to produce the recording signal
per one picture element, whereby reproducing a combination of the
picture and the character on a photosensitive material.
BRIEF DESCRIPTION OF DRAWINGS
In order that the present invention may be better understood,
preferred embodiments thereof will be described with reference to
the accompanying drawings, in which:
FIG. 1 is a block diagram of a layout color scanner which carries
out a method according to the present invention
FIG. 2 is an enlarged view of a halftone picture including a part
of a character therein, reproduced by a method according to the
present invention;
FIG. 3 shows picture elements of picture and picture elements of
character according to the present invention;
FIG. 4 shows a data format for storing a plurality of data for
picture elements of character in a character memory in
synchronization with an address according to the present
invention;
FIG. 5 is a block diagram of one embodiment of a coder shown in
FIG. 1;
FIG. 6 is a block diagram of one embodiment of a decoder shown in
FIG. 1;
FIG. 7 is a block diagram of another embodiment of a decoder shown
in FIG. 1; and
FIG. 8 is a block diagram of one embodiment of a halftone
dot-character selector shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings there is shown in FIG. 1 a layout
color scanner which carries out a method according to the present
invention and which comprises a picture scanning means 1, a
recording scanning means 2, and a layout means 3.
The picture scanning means 1 of a conventional type comprises a
picture cylinder 5 on which an original picture 4 is mounted, a
motor 6 for driving the picture cylinder 5 via a rotary shaft 7, a
rotary encoder 8 mounted to the rotary shaft 7, a pickup head 9 for
photoelectrically scanning the original picture 4, a screw rod 10
extending in parallel with the axis of the picture cylinder 5, on
which the pickup head 9 is movably mounted, and a motor 11 which
rotates the screw rod 10 so as to move the pickup head 9 along the
screw rod 10.
The pickup head 9 outputs an analog picture signal e.sub.1 to a
picture signal processing section 12 in which the analog picture
signal e.sub.1 is converted into a digital signal and is
color-controlled such as a masking correction, a color correction,
and a gradation correction in a conventional manner to obtain a
color-corrected digital picture signal d.sub.1 of a certain bits,
for example, eight bits. Thus the obtained color-corrected digital
picture signal d.sub.1 is sent to a memory 13.
The rotary encoder 8 outputs two kinds of timing pulses g.sub.1 to
a timing controller 14 which generates a clock pulse g.sub.2 for
converting the analog signal into the digital signal, and a start
pulse g.sub.3 for determining the scanning start point. The clock
pulse g.sub.2 is sent to the picture signal processing section 12,
and the clock pulse g.sub.2 and the start pulse g.sub.3 are sent to
an address signal generator 15 which controls addresses of the
memory 13 in the writing mode. The memory 13 possesses an address
space enough to store the picture signals d.sub.1 corresponding to
at least one original picture 4.
The recording scanning means 2 comprises a recording cylinder 17 on
which a photosensitive material 16 is mounted, a motor 18 for
driving the recording cylinder 17 via a rotary shaft 19, a rotary
encoder 20 mounted to the rotary shaft 19, a recording head 22
which projects a line of light beams 21 which are optically
modulated according to a recording signal, onto the photosensitive
material 16, a screw rod 23 arranged in parallel with the axis of
the recording cylinder 17, on which the recording head 22 is
movably mounted, and a motor 24 which rotates the screw rod 23 so
as to move the recording head 22 along the screw rod 23.
According to the present invention, the recording scanning means 2
can reproduce a halftone picture directly with a sufficiently
higher resolving power than that of the picture scanning means 1.
This higher resolving power can be obtained by using a plurality of
exposure light beams passing through, for example, ten light paths
L.sub.1 -L.sub.10, each exposure light beam having a finer pitch
than the moving pitch of the recording head 22 per one rotation of
the recording cylinder 17.
Each of the light paths L.sub.1 -L.sub.10, corresponding to the
digital signal of one bit, is independently controlled to be open
or close, thereby exposing the photosensitive material 16 to the
two-value states, i.e. the exposed and the unexposed parts such as
black and white. On this occasion, the digital picture signal
having the continuous gradation is converted into the corresponding
halftone dot area rate, resulting in recording of the halftone
picture.
A method and an apparatus for reproducing a reproduction picture
directly from the digital picture signals having the continuous
gradation have been developed, as disclosed in Japanese patent
application No. 56-55841 corresponding to U.S. patent application
Ser. No. 365,890, and thus the detailed description is omitted.
The rotary encoder 20 outputs two kinds of timing pulses g.sub.4 to
a timing controller 25 in which the timing pulses g.sub.4 are
converted into a clock pulse g.sub.5 having a necessary period for
producing a halftone dot, and a start pulse g.sub.6 for determining
the recording start point. These pulses g.sub.5 and g.sub.6 are
sent to a halftone dot signal generator 26.
The halftone dot signal generator 26 receives the digital picture
signal and outputs a light path open-close control signal l.sub.1
for recording a halftone dot pattern corresponding to the digital
picture signal. The light path open-close control signal l.sub.1 is
fed to a light path open-close controller 27 included in the
recording head 22 as a control signal l.sub.2 via a halftone
dot-character selector 38, as hereinafter described in detail. The
light path open-close controller 27 separates a light beam
generated by a laser 28 into ten light beams, each being controlled
to be passed or stopped by a light modulator such as an
acoustooptic modulator, or the like.
The layout means 3 comprises a central processing unit 29,
hereinafter referred to as CPU, such as a micro-processor a memory
30 for the layout, and an interface 31 connecting the CPU 29 and
the layout memory 30. A digital picture signal d.sub.2 read out of
the memory 13 is transferred to the layout memory 30 via the
interface 30 by properly addressing by means of the CPU 29
depending on the desired layout.
A key board 32, a character generator 33, a character memory 34, a
CRT monitor 35, and so forth, are connected to the CPU 29 via the
interface 31. The key board 32 inputs the necessary data for the
layout processing to the CPU 29. The character generator 33
generates the character to be composed into the original picture,
and the size and the style of the character are properly determined
by the key board 32. Picture elements of character, hereinafter
referred to as "character picture elements", differing from the
"picture element" of picture, which show the form of the character,
are once stored in the character memory 34 in the form of data
formats mentioned hereinafter.
The CRT monitor 35 monitors an image stored in the memory 13, an
image stored in the layout memory 34 in the course of the layout
and after the same, and the size and the position of the character
in the picture.
In this embodiment, the area of one picture element of picture
corresponds to a plurality of character picture elements, in other
words, one picture element area is divided into a plurality of
character picture element areas, and the data of these character
picture elements are stored in one address of the character memory
34 with the same bit number as that of the data which represents
the density of one picture element of picture.
However, there is no need that the bit number of the data of such
character picture elements is the same as that of the data of one
picture element of picture, and the data of the character picture
elements may be expressed by a larger bit number than the above in
order to increase the resolving power.
In this embodiment, one picture element area is divided into a
plurality of character picture element areas, for example, four
areas. While the data representing the density of one picture
element is expressed by one word of 8 bits, the data of the four
character picture elements corresponding to one picture element is
expressed by the lower four bits of an 8 bits binary code, and a
data for discriminating between the picture and the character and a
data for determining whether the density data of the picture is
added in the background of the character or not, as occasion
demands, use two bits of the remaining four bits as a separation
bit and a discrimination bit, respectively, as shown in FIG. 4.
In the character memory 34, the character picture elements which
are smaller than the picture elements of picture are stored with
the higher resolving power so that the character picture elements
may be interchangeable with the picture elements every one picture
element of picture.
The capacity of the character memory 34 depends on the size of the
character, the number of the characters to be processed in the same
time, and so forth. The capacity for storing the entire layout
space is unnecessary for the character memory 34, apart from the
layout memory 30.
A character signal c read out of the character memory 34 is fed to
a coder 36 and the picture signal d.sub.2 is also fed from the
memory 13 to the coder 36 via the interface 31. In the coder 36 the
two signals c and d.sub.2 are mixed, and a mixed signal m is sent
from the coder 36 to the layout memory 30. The layout memory 30 has
a capacity enough to store the maximum area processed by the
recording scanning means 2, and when the data is written in, the
picture and the characters are laid out in the certain layout
positions by addressing in a certain order.
After the completion of the layout operation, the mixed signal m is
read out of the layout memory by addressing in synchronization with
the recording scanning means 2, and the read out mixed signal m is
sent to a decoder 37 arranged between the layout memory 30 and the
halftone dot signal generator 26. The decoder 37 separates the
mixed signal m into the picture signal d.sub.2 and the character
signal c, and further separates the character picture signal bits
from the character signal c.
The picture signal d.sub.2 separated by the decoder 37 and a
background picture signal d.sub.3 hereinafter described are sent to
the halftone dot signal generator 26 as a picture signal d.sub.4.
The halftone dot signal generator 26 outputs the light path
open-close control signal l.sub.1 to the halftone dot-character
selector 38 positioned between the halftone dot signal generator 26
and the light path open-close controller 27 in the recording head
22. The halftone dot-character selector 38 overlaps the character
data onto the light path open-close control signal l.sub.1
depending on the data picked up from the character picture element
bits and the separation bit of the binary code, which are separated
by the decoder 37, as hereinafter described in detail.
In FIG. 2 there is shown an enlarged halftone picture including the
character, obtained in the manner described above, wherein the
picture is reproduced by means of the halftone dots 39 having a
halftone dot area rate of 12.5% depending on the density and the
part of the character 40 is shown. In FIG. 2, P.sub.1 means a
screen pitch, P.sub.2 means a pitch of the picture element of
picture, P.sub.3 means a pitch of a unit area for forming the
halftone dot in a mosaic pattern, and areas of picture elements S
of picture are divided by broken lines.
As shown in FIG. 2, ten light beams passing through the ten
exposure light paths L.sub.1 -L.sub.10 are aligned in series in the
moving direction of the recording head 22, and ten unit areas for
forming the halftone dot 39 are aligned in the scanning direction.
Therefore, in this embodiment, P.sub.2 =nP.sub.3 =10P.sub.3 is
satisfied, wherein P.sub.3 corresponds to the width of the scanning
line of the light beam. In the halftone dot structure shown in FIG.
2, the screen pitch P.sub.1 and the picture element pitch P.sub.2
are related as P.sub.1 =2P.sub.2.
In FIG. 3 there are shown the picture elements S and the four
character picture elements A, B, C and D which correspond to one
picture element S.
In the character memory 34, a set of character picture element data
(A,B,C,D), included in the picture element S, corresponds to one
address so that the four character picture elements A, B, C and D
may be freely interchangeable with one picture element S. The data
format of the character signal c is shown in FIG. 4.
Since the character is only expressed by the two values such as
white and black, each of the character picture element A, B, C and
D is represented by a data of one bit, and the lower four bits of
the one word of 8 bits are used for the four character picture
elements A, B, C and D.
In the higher four bits of the one word of 8 bits, the separation
bit E which indicates whether the recording area of the picture
element S includes the character picture elements A-D or not, and
the discrimination bit F which discriminates whether the background
picture is added to the recording area of the picture element S
including the character picture elements A - D are aligned in the
upper two bits of the lower four bits for the character picture
elements A-D, and 0 bits are aligned in the uppermost two bits so
that a value indicated by the lower six bits may be at most 64 of a
decimal value.
Meanwhile, the addresses of the layout memory 30 are controlled by
an address signal generator 41 so that the address numbers may be
changed at the period corresponding to the pitch P.sub.2 of the
picture element S. In the halftone dot signal generator 26, the
halftone dot signal is controlled in synchronization with the clock
pulse g.sub.5, generated by the timing controller 25, having a
period corresponding to the pitch P.sub.3 of. the unit area.
The clock pulse g.sub.5 is fed to a 1/n divider 42 in which the
clock pulse g.sub.5 is divided by a number n corresponding to the
exposure light beams, for example, ten in this case, to obtain a
pulse g.sub.7 having a period corresponding to the pitch P.sub.2,
and thus the obtained pulse g.sub.7 is sent to the address signal
generator 41.
The pulse g.sub.7 generated by the divider 42 is sent to a
monostable multivibrator 43 in which the pulse g.sub.7 is converted
into a pulse g.sub.8 having a duty cycle of 50% in order to obtain
a timing corresponding to a pitch P.sub.4 of the character picture
element, and this pulse g.sub.8 is sent to the halftone
dot-character selector 38.
In FIG. 5 there is shown one embodiment of the coder 36 of the
layout means 3 of FIG. 1, wherein the interface 31 is omitted.
The picture signal d.sub.2 read out of the memory 13 by the CPU 29
is fed to the first and the second compressors 44 and 45. The first
compressor 44 compresses the density steps of 0-255 of the picture
signal d.sub.2 to those of 0-191, while its bit number is
maintained to 8 bits, to obtain a second picture signal d.sub.2 '
which is sent to one channel of a data selector 46. The second
compressor 45 compresses the picture signal d.sub.2 having the
density steps of 0-255 to output another signal of 2 bits having
density steps of 0-3, which is sent to upper bits of one input
terminal of an adder 48 via an AND gate 47. The four bits data of
the character picture element A-D, output from the character memory
34, are input to lower bits of the one input terminal of the adder
48.
A data corresponding to a decimal value 192 is input to the other
input terminal of the adder 48. The adder 48 adds the values input
to the input terminals to output a second character signal c' of 8
bits having more than the decimal value 192 to the other channel of
the data selector 46.
The data selector 46 selects one of the data input to the channels
by the data of the separation bit E which is output from the
character memory 34, and outputs the mixed signal m to the layout
memory 30. On this occasion, when the data of the separation bit E
indicates that the recording area of the picture element S includes
the character picture elements A-D, the data selector 46 selects to
output the data sent from the adder 48.
To the data selector 46, the second picture signal d.sub.2 ' having
a decimal value of at most 191 and the second character signal c'
having a decimal value of at least 192 are input separately, and
the mixed signal m can be separated at the decimal value of
192.
The data of the separation bit E and the discrimination bit F are
sent to an AND gate 49, and, when both the data are "1", that is,
the character exists and the background picture is to be added, the
output signal of the AND gate 49 is fed to the AND gate 47 and
opens the same, thereby sending the output data of the second
compressor 45 to the adder 48.
The output data of the second compressor 45 is compresse to four
kinds of density steps of 0-3, as described above. In this case,
the input density value ranges, the compressed values, the
converted density values or the extended values of the decoder, and
the halftone dot area rates are tabulated in Table 1, wherein the
values are shown in decimal number.
TABLE 1 ______________________________________ Converted Density
Input Density Compressed Value (Extended Halftone dot Value Range
Value Value) Area Rate % ______________________________________
0-63 0 0 0 64-127 1 64 25 128-191 2 128 50 192-255 3 192 75
______________________________________
The writing addresses of the layout memory 30 are controlled by the
CPU 29, and the picture signal d.sub.2 and the character signal c
which are to be written in the layout memory 30, are read out of
the memory 13 and the character memory 34 by addressing the
predetermined addresses by means of the CPU 29. In these
circumstances, the picture signal d.sub.2 is read out of the memory
13 regardless of the character signal c and the character signal c
is read out of the character memory 34 by the order of the CPU 29
only when the addresses of the layout memory 30 are come up to
those for storing the character. In the code 36, the character
signal c is preferentially processed.
Consequently, the character memory 34 may have the capacity enough
to store the maximum character data to be processed, and thus need
not the capacity for storing the entire layout addresses. Further,
depending on the processing by the CPU 29, the processing can be
carried out every character, and hence the capacity of the
character memory 34 can be reduced to that for one character of the
maximum size.
In FIG. 6 there is shown one embodiment of the decoder 37 of FIG.
1, which decodes the picture signal d.sub.2 and the character
signal c from the mixed signal m read out of the layout memory
30.
The mixed signal m read out of the layout memory 30 is fed to one
input terminal of a magnitude comparator 50, an expandor 51, and a
minuend input terminal of a subtracter 52.
The magnitude comparator 50 compares the mixed signal m with the
binary code representing the decimal number of 192 which is input
to the other input terminal of the magnitude comparator 50. When
the mixed signal m is larger than the binary code representing the
decimal number of 192, the magnitude comparator 50 outputs the data
of the separation bit E which indicates that the mixed signal m is
the second character signal c', to the halftone dot-character
selector 38
The expandor 51 expands the span of 0-191 of the second picture
signal d.sub.2 ' having the density steps of 0-191 to the span of
0-255 by a code converter having a table, such as a ROM (read only
memory), thereby obtaining a picture signal d.sub.3 having 192
density steps, which is sent to one input channel of a data
selector 54.
The subtractor 52 subtracts the value corresponding to the decimal
number of 192 from the mixed signal m, and when the mixed signal m
input is the second character signal c', the subtracter 52 outputs
a code of 6 bits having the same bit pattern as the input signal of
the adder 48.
The code of the upper two bits of the output signal of the
subtracter 52 is sent to a code converter 53 in which the two bit
code representing a decimal value of 0-3 is converted into a code
corresponding to a density signal of 8 bits, as shown in Table 1,
which is sent to the other input channel of the data selector 54.
The code of the lower four bits of the output signal of the
subtracter 52 is sent to the halftone dot-character selector 38 as
a code of the character picture elements A-D.
The data selector 54 outputs a signal d.sub.4 to the halftone dot
signal generator 26. That is, the output of the data selector 54 is
so selected by the data of the separation bit E that, when the data
of the separation bit E indicates that the mixed signal m is the
second character signal c', the data selector 46 may send the
output signal for the background picture from the code converter 53
to the halftone dot signal generator 26, or when the data of the
separation bit E indicates that the mixed signal m is the second
picture signal d.sub.2 ', the data selector 46 may send the picture
signal d.sub.3 of the expandor 51 to the halftone dot signal
generator 26.
In FIG. 7 there is shown another embodiment of the decoder 37 of
FIG. 1, which comprises a ROM table 55. In this embodiment, the
mixed signal m is decoded to the signal d.sub.3, the code of the
character picture elements A-D, and the code of the separation bit
E by.the ROM table 55 which outputs the data of 13 bits by
addressing the data of 8 bits.
In FIG. 8 there is shown one embodiment of the halftone
dot-character selector 38 of FIG. 1.
The halftone dot signal generator 26 outputs ten bits of light path
open-close control signals l.sub.1 to one input terminals of ten OR
gates 56-65, and the output signals of the ten OR gates 56-65 are
sent to the light path openclose controller 27 as the control
signal l.sub.2 which control the light paths L.sub.1 -L.sub.10 to
open or close them independently.
An AND gate 66 selectively passes the data of the character picture
elements A and C and outputs a signal to the OR gates 56-60, in
common, and an AND gate 67 selectively passes the data of the
character picture elements B and D and outputs a signal to the OR
gates 61-65, in common.
These AND gates 66 and 67 are controlled by the data of the
separation bit E to be opened or closed, i.e. when the data of the
separation bit E indicates that the mixed signal m is the second
character signal c', the AND gates 66 and 67 are opened by the data
of the separation bit E, thereby passing the data of the character
picture elements A-D.
In a multiplexor 68, the data of the character picture elements A
and C and the data of the character picture element B and D are
changed alternately every half pitch of the picture element pitch
P.sub.2 by the pulse g.sub.8 generated by the monostable
multivibrator 43, resulting in outputing the data of the character
picture elements A and B or C and D to the AND gates 66 and 67.
When the data of the separation bit E indicates that the mixed
signal m is the second character signal c', the signal d.sub.4
input to the halftone dot signal generator 26 is the signal
representing the background picture, and the light path open-close
control signal l.sub.1 obtained by this signal d.sub.4 passes the
OR gates 56-65. On this occasion, the halftone dot of dots are
recorded in the character picture element area or areas in which
the character may not be recorded.
When the white character is recorded in the dark background, the OR
gates 56-65 are replaced with the corresponding number or AND
gates, and the AND gates 66 and 67 are changed by NAND gates.
It is readily understood from the above description that according
to the present invention a reproduction picture including a picture
and a character is recorded by a mixed signal which is obtained by
mixing a picture signal and a character signal and which is stored
in the same address of a layout memory. However, the present method
is not restricted to this method, for example, the picture signal
and the character signal are selectively fed to the halftone
dot-character selector from a conventional layout system or a
conventional photo-composing system.
According to the present invention, when the reproduction picture
including the picture and the character is recorded in the desired
layout positions, the picture signal having a continuous gradation
and the character signal having two-value levels are processed in
parallel to produce the mixed signal by selectively outputting one
of the two signals, and then the reproduction picture is recorded
by using one recording head according to the obtained signal.
In the embodiment described above, the character can be reproduced
faithfully with the higher resolving power than the picture by
recording the finer character picture elements than the picture
elements of the picture.
Although the present invention has been described in some detail by
way of illustration and example for purposes of clarity of
understanding, it will, of course, be understood that various
changes and modifications thereof may be made in the form, details,
and arrangements of the parts without departing from the scope of
the present invention.
For example, one of the memories 13 and 30 of the picture scanning
means 1 and the layout means 3 can be omitted by using a buffer
memory having a small capacity while the one memory is used, in
common, for the picture scanning and the layout.
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